Humans have been fighting each other for centuries. They formed tribes, built great kingdoms, and constantly sought ways to protect what was theirs. They would do anything possible to stop invaders from coming into their land.

One obvious way to stop anyone from coming towards us is to make a barrier, a wall.

The process of making these defensive walls is called the Fortification. Fortifications are military structures designed to protect territories in times of war and maintain control during peace.

From very early history to modern times, such defensive walls have often been built and in fact were necessary for cities to survive in an ever-changing world of invasion and conquest.

But among all the walls ever built, one stands out as the greatest of them all—the Great Wall of China.
 

The Great Wall of China stretches to an astonishing length of over 21,000 kilometres which is more than 13,000 miles.

If we build a wall along entire Canada–U.S. border, we can build two such walls.

And if we are in India and build a wall running all the way from Ladakh to Kanyakumari, we would have to build 7 such walls to match the length of the Great Wall, and still, we would fall short.
 

The Great Wall wasn’t built all at once. In fact, it’s not just one wall—it’s a series of fortifications built by different states over time.

Thousands of years ago, China wasn’t the unified country we know today. Back then, it was a land of warring states, where powerful rulers constantly fought over land and resources.

To protect their territories, each state built its own defences — walls. Construction of these walls began in the 7th century BCE. They were primarily made of stone and rammed earth, a technique that involved compacting earth and gravel between board frames, layer by layer, to form solid barriers.

These walls were built to withstand the attack of small arms such as swords and spears.

Some of these walls were small, others were massive. But none of them were connected. Not yet.

Then came Qin Shi Huang—the first emperor of China. He conquered every rival state and successfully unified China. He, then ordered the destruction of the sections of the walls that divided his empire among the former states.

However, the threat of invasion from the north by tribes like the fearsome Xiongnu and Mongols remained. So, Qin Shi Huang, ordered to construct new walls and to connect the existing scattered walls to create one massive barrier stretching across the northern frontier.

But building such a vast structure came with significant challenges. It required an enormous amount of materials, and transporting them over mountains and deserts was very difficult.

So, builders used local resources for the project, just like we strive to do in modern times. Using the local resources immensely reduces the cost and time of the construction while improving the smoother work flow.

For the Great Wall, they used stone in the mountainous areas, and rammed earth while building across the plains.

But let’s be clear — it wasn’t just a wall they were building. It was an entire defensive system. They built garrisons where soldiers lived and operated from. These also served as storage areas for weapons and food.

They also developed an early warning system using beacon towers, where smoke during the day or fire at night was used to send messages quickly across long distances.

And in addition to all that, they built watchtowers to keep an eye out for invaders.

All of this massive effort was overseen by the emperor’s famed military general, Meng Tian.

According to ancient Chinese beliefs, the earth was thought to have energy lines running through it. Meng Tian believed that by digging, cutting, and reshaping the land, he had not only caused physical damage—but also disrupted the earth’s natural energy, creating spiritual imbalance.

Near the end of his life, he even expressed regret for his actions, saying:

It’s a powerful reminder that even grand projects can leave a mark — not just on the land, but on the people behind them.

Unfortunately, we don’t have exact historical records showing the full length or path of the original Qin walls. Over the centuries, most of these ancient fortifications have eroded away, and only a few scattered sections remain today.

Later dynasties repaired, rebuilt, and expanded different sections of the Great Wall. Its purpose was no longer just to defend against northern invaders. Over time, it became a network of watchtowers, forts, and military outposts — used for border control, trade protection, and managing movement across the empire.

But the best-known sections of the Great Wall were built during the Ming dynasty (1368–1644). These are the parts most people recognize today—the ones we see in photos and on postcards.

The Ming undertook a defensive building program on a scale never seen before in Chinese history. Unlike earlier dynasties, they used bricks, stones and other materials such as tiles and lime instead of rammed earth that was used to build earlier walls. These materials made the Wall stronger, more durable, and better able to withstand both attacks and weathering.

Bricks, in particular, had some big advantages—they were easier to handle than bulky stones or rammed earth, which sped up the construction process. Additionally, bricks could bear more weight and last longer than rammed earth. To hold the bricks together, the Ming builders used a surprisingly effective mix called sticky rice mortar—a blend of sticky rice soup and slaked lime that made the walls even more durable.

Stone, on the other hand, was tougher to work with but are great for strength, so it was used mainly for the foundation, outer edges, and gateways—places that needed extra support.

But using bricks and stone came with new challenges. Earlier builders could use local earth and gravel, but now the Ming had to set up brick kilns and quarries. They also needed reliable transport routes to move these heavy materials to remote construction sites.

But that wasn't all. Building with bricks required a higher level of skill than working with rammed earth. Local peasants, who had helped with earlier constructions, didn’t have the training for this kind of work. So, the Ming had to hire skilled masons to ensure the walls were built to last. All these changes meant a significant increase in construction costs.

The Ming also replaced earlier dry-stone walls with stone and mortar. This made the walls stronger and allowed them to build on steeper, more easily defended slopes. It also made it possible to add extra defensive features like raised walkways, notched battlements, and peepholes for watching the enemy.

These battlements ran along the top of most sections of the wall and were lined with defensive gaps called crenellations—perfect for archers to shoot through while staying protected behind the stonework. From these parapets, guards could keep a close eye on the surrounding land.

But just defending a spot wasn’t enough. Communication along the Wall was critical — whether to warn of an incoming invasion or to call for reinforcements. So, the Ming built signal towers high up on hilltops, where smoke signals could be seen from miles away.

The Ming devoted considerable resources to repair and reinforce the walls. They are estimated to have built up to 25,000 watchtowers along the wall. For the first time, they introduced hollow watchtowers to the wall.

Until then, most towers along the Great Wall were solid structures with a small hut on top for soldiers to take shelter from the incoming arrows.

The new hollow brick towers provided interior space for soldiers to live, store food and water, stockpile weapons, and find shelter from enemy arrows. This innovation significantly improved the wall's defensive capabilities and the living conditions for the soldiers stationed there.

The Ming didn’t just build walls — they pushed boundaries. They extended the Wall across rough and mountainous terrain that had once been considered impossible to cross. This gave the iconic views of the stone-faced Great Wall winding and snaking dramatically over hills and cliffs for which tourists from all around the globe flock to see today.

The sections near the Ming capital, Beijing were especially strong. In fact, in some places the Wall was reinforced with two, three, or even four parallel lines of defence.

A modern archaeological survey revealed that the full stretch of the Ming Great Wall measures 8,850 kilometres — or about 5,500 miles — across northern China.

But time hasn’t been kind to it. A 2012 report by the National Cultural Heritage Administration found that around 22% of the Ming Wall has already disappeared due to natural erosion, human activity, and neglect.

Here’s something interesting — the Great Wall remained somewhat of a mystery to the Western world for centuries. European travellers, missionaries, and merchants who visited China had wrote about its existence, but none actually saw it with their own eyes.

Even the famous 14th-century explorer Ibn Battuta, after hearing stories about the Wall, said he couldn’t find anyone who had actually seen it — or even knew someone who had.
 

Today, the Great Wall stands not just as a monument of stone and brick, but as a symbol of China’s enduring strength and ingenuity. It’s one of the most remarkable feats of architecture and engineering in human history. Recognized as a UNESCO World Heritage Site, it was also voted one of the New 7 Wonders of the World in 2007.

It is located in the northern china, with the sea at one end and the desert on the other.

The Wall’s easternmost tip, where it meets the sea, is called the Old Dragon Head — because it resembles the head of a mighty dragon.

And the Great Wall itself is often described as a giant dragon snaking across northern China — winding over mountains, through valleys, and across deserts.